1. Field of the Invention
This invention relates to a new polypeptide of unknown structure which exhibits biological activity, including vasoactivity, said polypeptide having been found in and extracted from neural tissue.
2. Description of the Prior Art
It is well known that polypeptide hormones regulate many physiologic functions and mediate certain pathological responses. While numerous compounds have been known to possess a vasodilator effect, many possess this effect only to a relatively slight degree or for a very short time. Medical science has therefore sought materials exhibiting a more potent or sustained vasodilator effect and which would be more useful therapeutic agents.
In prior U.S. Pat. Nos. 3,879,371; 3,880,826; 3,862,927 and 3,898,329, there is disclosed a new polypeptide indentified as a Vasoactive Intestinal Peptide which polypeptide is a 28 residue peptide structurally and biologically related to secretin and glucagon. The VIP polypeptide was originally isolated from porcine duodenum and was found throughout the gastrointestinal tract of mammals and birds. This polypeptide exhibited a wide variety of therapeutic biological actions including systemic vasodilation, hypotension, increased cardiac output, respiratory stimulation, hyperglycemia, coronary dilation and bronchodilation in animals and humans.
The present invention provides a new polypeptide of unknown structure which has been extracted from neural tissue and has been detected as being present in other tissue. The polypeptide of this invention is related to the vasoactive intestinal peptide of these prior patents and may exhibit similar therapeutic actions.